软土地区曲线段盾构隧道超挖量与注浆量分析

Analysis of Over-excavated Volume and Synchronous Grouting Volume for the Shield Tunnel at Curved Section in Soft Soil Area

对软土地区盾构施工过程中曲线段因盾构超挖产生的空隙进行了理论计算,并对直线段与曲线段的同步注浆量进行了比较,结果表明:盾构在曲线段盾构推进过程中,因盾构超挖侧面的土体发生了坍塌与变形,在盾尾到达超挖间隙前已被周围坍塌与变形的土体所填充;在采用注浆压力进行同步注浆控制时,在曲线段并未因盾构超挖而导致实际注浆量明显增加。为了减小曲线段因超挖导致的地表沉降,在曲线段盾构推进时应适当加大同步注浆压力,建议以直线段同等注浆率对应的注浆量作为同步注浆控制标准。

The over-excavated clearance generated by over excavation in soft soil area has been calculated theoretically, and the synchronous grouting volume at straight section and curved section has been compared. The result showed that：The collapse and deformation of the soil around the over-excavated clearance occurred before the shield tail reached the clearance, and the over-excavated clearance was filled by the soil. The synchronous grouting volume at the curved section did not increase for the over-excavated clearance. In order to decrease the ground settlement of the curved section, synchronous grouting pressure should increase properly, and the synchronous grouting volume which has the same grouting rate as that for the straight section can be used as the synchronous grouting standard.